VI. Choose the correct modal verb to complete the sentences.
1. In a library, students (may / must) borrow up to six books.
2. In an exam, students (must / mustn't) answer all the questions.
3. To ride motorbike, students (must / have to) be over 16 years old.
4. In a hotel, guests (must / have to) use the exit only in an emergency.
5. In a park, you (must / mustn't) walk on the grass.
6. On a bus, you (must / mustn't) talk to the driver.




